Klingspor



Feb. 3, 1959 c. KLINGSPOR I 2,871,633

GRINDING BODIES Filed Sept. 26, 1956 Arrow:

GRINDING BODIES Carl Klingspor, Siegen, Germany Application September 26, 19 6, Serial No. 612,135 b I l 3 Claims. eter-207 The present invention is concerned with improvements in or relating to grinding bodies, in particular those comprising a supporting member and a grinding member consisting of layers of fibrous material covered with abrasives, which is attachcdvto the supporting member.

In one type of known grinding disc of this kind, the supporting member consists of a steel plate with recesses and holes around its periphery, on to which is afiixed an abrasive mass by means of a synthetic resin bond. These grinding discs have a relatively high weight owing to the steel plate and are rendered expensive by the steel plate itself and by the necessity of the grinding edge having to be very strong and thick. In addition the steel plate cannot always be re-covered after the grinding edge has been worn away.

Grinding discs are also known which consist of a steel supporting disc onto which is aflixed a grinding ring consisting of layers of fibrous material covered with abrasives.

A disadvantage of all these known grinding discs is that the grinding ring is not sufiiciently strongly attached to the supporting disc, so that when such grinding discs are used in high speed machines there is a danger of the grinding ring breaking and being thrown oil the supporting disc.

It is therefore an object of the present invention to provide a grinding body comprising a supporting member and a grinding member consisting of layers of fibrous material covered with abrasive afiixed thereto, in which the grinding member is very securely attached to the supporting member and in which the disadvantages of a steel supporting member are avoided.

According to the present invention, there is provided a grinding body comprising a grinding member formed from layers of abrasive-covered fibrous material, which is carried by a supporting member formed from compressed layers of fibrous material, the layers .of the grinding member and of the supporting member being bonded together and the grinding member being bonded to the supporting member by a hardened synthetic resin.

The abrasive covered fibrous material is preferably abrasive paper and the grinding member is preferably provided with grooves, depressions or profiles in order to facilitate the grinding action. For certain applications it is also desirable to increase the porosity of the grinding member by the incorporation of cork or similar materials therein.

In one embodiment of the invention, the grinding member is in the form of a ring secured around the periphery of the supporting member which is in the form of a disc. In such an embodiment the grinding member is preferably formed from a plurality of superimposed rings, alternate rings having a smaller internal diameter than the adjacent rings and the supporting member is formed from a plurality of superimposed discs, alternate discs having a smaller diameter than the adjacent discs, the grinding member being mounted around the periphery of the supporting member such that rings of smaller in- United States Patent 0 2,871,633 Patented F eh. f 3, 1

ternal diameter are aligned with discs of smallerdiameter and rings of larger internal diameter-with discs of larger diameter.

' In order that the invention may be more fully understod, certain preferred embodiments of the invention will now be described, by way of example only, withrefer ence to the accompanying drawings, in which: I

Figs. 1 and 4 are plan views of two types of abrasive covered rings for use in grinding bodies according to: the invention, i c;

Figs. 2 and 3 are plan views .of=two types of discslifor use in grinding bodies according to the invention,

Fig. 5 is a sectional view showing the assembly of one embodiment of the invention,

Figs. 6, 7 and 8 are sectional views showing various stages in the assembly of a second embodiment of the invention, and

Fig. 9 is a sectional view showing the assembly of a third embodiment of the invention.

Referring to Fig. 1, an abrasive covered ring suitable for the formation of the grinding member of a grinding body according to the invention comprises a ring 1, having an external diameter of 400 mm. and an internal diameter of 200 mm., stamped out from a sheet of fibrous material impregnated with hardenable synthetic resin, onto which is glued abrasive grains 2 by means of a hardened synthetic resin bond. Discs of fibrous material impregnated with hardenable synthetic resin suitable for the formation of the supporting member of a grinding body according to the invention are shown in Figs. 2 and 3, disc 4 of Fig. 2 having a diameter of 200 mm. and disc 3 of Fig. 3 having a diameter of 240 mm.

An assembly of rings 1 and discs 3 and 4 to obtain a grinding body in accordance with the invention is shown in Fig. 5. This assembly is made up as follows:

One abrasive coated ring 1.

One disc 3.

Two discs 4.

One abrasive coated ring 1.

Rings 1 and discs 3 and 4 are laid upon one another in this order, as shown in Fig. 5, until the amount of material required for the desired thickness of the grinding body has been assembled. The assembled material is then completely bonded together in a synthetic resin press using, for example, a pressure of kgs. per sq. cm. at a temperature of C.

The production of a second embodiment of the invention is illustrated in Figs. 6, 7 and 8. Referring to Fig. 6 the supporting member of this embodiment is made up of interlayed discs 3 and 4, which are compressed together when sufficient material has been assembled. The grinding member of this embodiment is made up, as illustrated in Fig. 7, of interlayed rings 1 and rings 5, shown in Fig. 4, which are similar to rings 1 but have an internal diameter of 240 mm. The grinding member thus obtained is laid over the supporting member and the two are bonded together under heat and pressure to give the grinding body illustrated in Fig. 8 which comprises the supporting member 6 and the grinding member 7.

A third embodiment of the invention is illustrated in Fig. 9. In this embodiment the supporting member is made up of five superimposed layers of synthetic resin impregnated fibrous materal 8 and five superimposed layers of abrasive coated fibrous material 9. The assembled material, is then bonded together in a heated pressing using, for example, a pressure of 150 kgs. per sq. cm. at a temperature of 150 C.

I claim:

1. A grinding body comprising a grinding member formed from a plurality of superimposed layers of abrasive coated fibrous material in the form of rings, alter-- nate rings having a smaller internal diameter than the the grinding member being mounted around the periphery of the supporting member such that rings of smaller internal diameter are aligned with discs of smaller diameter and rings of larger internal diameter with discs of larger diameter, said rings and discs being bonded together and to each other by a hardened synthetic resin,

whereby the grinding body consists of outer circumferential portions of said abrasive coated fibrous material and inner circumferential portions of fibrous material which are devoid of the abrasive coating.

2.- A grinding bodyaccording to claim 1, wherein the 15 difierence between the internal diameters of each pair of rings is the same and is equal to the difference between the diameters of each pair of discs.

3. A grinding body according to claim 1, wherein the grinding member is provided with grooves in order to facilitate the grinding action.

References Cited in the file of this patent UNITED STATES PATENTS 334,671 Laughton Jan. 19, 1886 1,045,016 George et a1 Nov. 19, 1912 1,435,721 McIntosh et a1 Nov. 14, 1922 2,094,556 Anderson Sept. 28, 1937 

